I believe I have previously photographed this individual with a full tail... It was nesting in hollow log nest was made of a pile of grass... I have been assuming it's a brown rat but had limited angles to emphasise the distinguishing features. These images were taken with the animal up a gum tree of some kind. In a Grove of various native trees.
Only 3 rattus in area. Short tail is indicative of R. fuscipes (bush rat) BUT tail may be missing a piece or not visible in images; Also Bush Rat hardly ever climbs and no longer occurs in urban area. R norvegicus (Sewer Rat) is locally rare and doesn't climb much. Long ears look like R.rattus (Black/Roof Rat) which climbs trees readily to forage for bird nests, fruit etc. SO R.rattus.
Ah thanks you for the information Don! I wasn't aware bushrats rarely climb trees and was unsure if there were any extant populations in Canberra. It's definitely missing a section of tail. I'd previously decided it was a black or brown rat not a bush rat because the tail was significantly longer than the body. It's very helpful to know that we only get r.rattus here too.